Slitters of the type involved herein are known to those skilled in the art. For prior art relating to slitters having operative sets of blades as well as inoperative blades in an idle zone on the same shafts, see U.S. Pat. No. 4,010,677. For prior art with respect to the concept of having an expandable shaft which facilitates simultaneous locking of all blade heads to the shaft, see U.S. Pat. No. 4,162,643. The last mentioned patent also discloses the concept of a master shifter for simultaneously shifting mating blades on a set of parallel shafts.
The present invention is directed to a solution of a problem which exists in each of said patents. When all blades on parallel shafts are simultaneously locked and unlocked with respect to the shafts, it is conventional to have some of the blades operative and others which are inoperative. It is desirable to have a simple arrangement for moving the sets of inoperative blades apart so that they do not rub against each other while permitting the operative blades to be in mating contact for performing their intended function. If the inoperative sets of blades are in rubbing contact with one another, they create a drag force which must be overcome and the blades wear out faster. The present invention is directed to a solution of this problem.